Improvement in projectiles for smooth-bored ordnance



v J. A. WOODBURY.

Projectile.

Patented Dec. 3, 1861.

UiTE STATES 'fA'rnNr FFEQE.

IMPROVEMENT IN PROJECTILES FOR SMOOTH-BORED OR DNANCE.

Specification forming part of Letters Patent No. 33,863, dated December 3, 1861.

To all whom it may concern..-

Be it known that I, JAMEs A. \VooDBUnY, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new-and useful Improvement in Projectiles; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, making part of this specification, in which-- Figure 1 is a plan of my improved'proiectile complete. Fig. 2 is a similar View with the sabot removed. Fig. 3 is a rear elevation of the sabot. Fig. 4 is a transverse section at w a", Fig. 1.

Similar letters of reference indicate corre sponding parts in the several figures.

The nature of my invention consists, first, in forming the external oblique channels by which rotation is imparted to the shot of greatest depth at the greatest diameter of the shot, and decreasing gradually in depth toward the front and rear, in order to present the smallest possible area of resistance to the passage of the shot through the air, apply the greatest lateral pressure of the air at the point where it can exert the greatest rotative force, and provide for the easiest possible reception, passage, and delivery of the current; second, in the use of a sabot spirally or obliquely winged or grooved, so as to receive rotation by the action of the escaping gases in the act of firing, in combination with a projectile winged or grooved in the opposite direction, so as to receive rotation by the action of the atmosphere during the flight of the shot, as hereinafter explained. I

To enable others skilled in the art to make and use my invention, I wi'll proceed to describe its construction and operation.

A is the projectile proper, and B the sabot. The external form of the front part of the projectile is conoidal or spheroidal, converging forward. The rear part (being, say, three fifths of the whole length) is in the form of a conic frnsturn converging backward.

a a a represent a series of oblique o r spiral grooves or channels, commencing-at or near the front end of the projectile, increasing in depth until reaching the greatest diameter of the shot, and thence decreasing backward to ihe rear end. The increase in the depth of he channels is not, however, so great as the operate withthe channelsa in causing the rov tation of the shot by the action of the atmosphere during its flight. The ofice of the sabot B is to give direction to the shot in its passage through the bore, close the windage so far as may be desirable, and protectthe channels a from the disadvantageous action of the gases escaping in the act of firing. The sabot is accordingly formed to fit over the rear'of the shot, and approaches on its exterior to a cylindrical form, but it is further provided with a series of oblique or spiral channels, I), beginning at the distance of, say, one inch from the the front of the sabot and increasing rapidly in depth to the rear.en'd.- The ofiice of the saidchannels is to inaugurate, by the action of the escaping gases, a-rotation which will be kept up and perhaps increased by the action of the atmosphere'upon the faces 1 of the channels a. The obliquity of the channels I) is accordingly opposite in direction to that of the channels a, in order that both may operate in the same direction upon the shot. To secure the communication to the shot of any rotation imparted to the sabot by the escaping gases, the sabot is provided in its interior with projections d, fitting within the channels a, as clearly shown in Fig. 4. In the illustration heregiven the shot passes into the sabot until arrested by its increasing size. If preferred, they may fit more loosely, the sabotjextending forward to'shoulders 6 upon the shot,

in order to prevent any danger of locking together so tightly in firing as to prevent the shot from disengaging itself from the sabot.

In using this invention the purpose is to leave suflicient windage between the front part of the sabot and the bore as to permit someescape of gas, in order. to enable it to act upon the channels I). This imparts a r0- tary motion to the shot before leaving the gun, which motion is continued in the same direction by .the action of the atmosphere in the channels a. The instant the sabot is relieved of pressure from behind the resistance of the cases 1. Channeling or grooving, in the manner atmosphere against its forward end causes the explained," the surface of an elongated prosho't to pass out at it-a n effect which is projectile tapering toward both ends, for the purmoted by the action of the air upon the chan- .pose of producing the greatest rotative force nels b tending to arrest the rotation of the sa- 'with the least possible atmospheric resistance.

bot. The shot thus released passes through the air with but slight resistance, the atmosphere rushing freely through the channels a and acting throughout the whole'length of the shot upon the faces 1, thus continuing and increasing the rotation which has been begun.

I am aware that spirally-winged bolts have previously existed, and do not desire to be understood as claiming any device consisting of wings projecting from a mere shaft or snindie of small diameter. Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

2. The use of a sab winged or gro by the action of the'gases escapingin the act of firing in the described combination with a projectile spirally Winged or grooved inthe opposite direction so as to receive acorresponding rotation by the action of the atmosphere during its'iflighu ot spir 'lly or obliquely oved, so as to aeceive rotation JAMES A, WOODBUBY.

Witnesses:

OGTAVIUS KNIG 

